Perennial herb from strongly creeping rhizomes; stems erect, numerous, branched, 1-2 m tall, reddish-brown.
Basal leaves lacking; stem leaves alternate, lanceolate, the blades up to 20 cm long, densely soft- hairy, the base rounded to somehat heart-shaped, often with 2 small lobes, the stalks short; stipules sheathing, entire.
Inflorescence a wide, diffuse panicle; perianth segments white, 3-5 mm long, not keeled on the back.
Apparently sterile in our range.
Synonyms and Alternate Names:
Polygonum polystachyum Wall. ex Meisn.
Persicaria wallichii is considered an emerging invasive species in the Vancouver region by the Greater Vancouver Invasive Plant Council (2009). An emerging invasive is defined by them as: currently found in isolated, sparse populations but are rapidly expanding their range within the region.